Secular trends in risk factors for adolescent anxiety and depression symptoms: the Young-HUNT studies 1995-2019, Norway.

In recent decades, increases in mental health problems in adolescents have been reported from several large population-based surveys. This raises questions about changes in underlying risk and protective factors that can inform future intervention strategies. Population data were collected from 1995 to 2019 in three waves of the Young-HUNT studies in Norway to map decennial trends in the prevalence of established risk factors for, and their associations with, adolescent mental health problems. All adolescents (aged 13-19 years) attending lower and upper secondary school in the county of Trøndelag were invited, representing three historical cohorts of 25,245 unique adolescents. Mental health problems (HSCL-5) and established mental health risk factors were self-reported. Using a generalized linear model and linear regression, we calculated changes in relative and absolute differences between risk factors and mental health problems. Overall, the prevalence of established risk factors for mental health problems in adolescence increased markedly between 1995 and 2019, especially in girls. Prominent increases were observed for fatigue, bullying, musculoskeletal pain and migraine, loneliness, and overweight. Furthermore, with the exception of excess alcohol use and family economy, associations between each risk factor and adolescent mental health problems strengthened over the same time span in girls, but less among boys. Our findings suggest that several modifiable risk factors for poor mental health in adolescence are increasing, especially among girls, and should be targeted in community, school, and in clinical settings.